Effectiveness of Bictegravir/Emtricitabine/Tenofovir Alafenamide in Virologically Suppressed People with HIV on Any Antiretroviral Therapy Regimen: The Retrospective ESSENTIAL Study

Introduction: Real-world evidence on the effectiveness and durability of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) as a switch strategy in virologically suppressed people with HIV (PWH) is important for clinical decision-making, particularly in ageing populations with multiple comorbidities and concomitant medications and in individuals previously treated with rilpivirine. Methods: ESSENTIAL (GS-IT-380-7059) is a retrospective, single-centre observational study including adults with HIV-RNA < 50 copies/ml who switched to BIC/FTC/TAF between July 2019 and April 2024 at ASST Fatebenefratelli Sacco, Milan, Italy. The primary endpoint was the virological suppression rate (HIV-RNA < 50 copies/ml) evaluated at 6 and 12 months after switching to BIC/FTC/TAF (observed-case analysis of available data). Secondary endpoints included treatment durability (Kaplan-Meier estimates of time to treatment interruption for any cause) and safety. A prespecified subgroup analysis evaluated individuals switching from rilpivirine/emtricitabine/tenofovir alafenamide (RPV/FTC/TAF). Results: Overall, 799 individuals were included (median age 53 [IQR 45, 58] years; 83% male). The cohort reflected substantial clinical complexity: 82.6% had ≥ 1 comorbidity (predominantly metabolic) and 34.2% were taking ≥ 3 concomitant medications; potential drug-drug interactions with the pre-switch antiretroviral regimen were identified in approximately 14% of cases. After the switch, virological suppression was maintained in 97.4% of participants at 6 months and 98% at 12 months. In the subgroup switching from RPV/FTC/TAF (n = 103), virological suppression rates were 93.9% at 6 months and 98% at 12 months, with only two confirmed virological failures. Kaplan-Meier analysis showed high treatment durability with few discontinuations, most of which were unrelated to virological failure or adverse events. Adverse events were infrequent (0.8% at 6 months; 0.3% at 12 months), with no unexpected safety signals during follow-up. Conclusion: In this large real-world cohort of virologically suppressed individuals, characterized by ageing, high comorbidity burden, and frequent concomitant medication use, switching to BIC/FTC/TAF was associated with sustained virological control and good tolerability over 12 months, including among those transitioning from RPV-based regimens. These findings provide additional real-world evidence supporting BIC/FTC/TAF as a durable and well-tolerated switch strategy in routine clinical practice.